IQ-Steel® – for design beyond present fatigue limits

IQ-Steel (Isotropic Quality) is an isotropic quality ultra clean steel optimized for fatigue strength by a strict control of steel cleanliness. IQ-Steel is a smart solution for designing reliable components that can take the strain from higher and more complex loads. It offers uniform and excellent properties in all loading directions.

Increased bending fatigue through purity

IQ-Steel, a further development of BQ-Steel, is an isotropic and ultra clean steel with properties that match remelted steels. Based on thousands of examinations by Ovako into the effects of defects on fatigue performance, the metallurgy of IQ-Steel is purer and far more consistent than conventional grades, and designed specifically to perform well in multiaxial loading. This enables the manufacturing of lighter, slimmed down components like gears, bearings and other critical parts. The steels are helping our customers to achieve new design solutions and implement higher standards of finished product performance. Key to these practical advantages are Ovako’s own unique, clean and consistent modern steelmaking processes that remove harmful inclusions and impurities from within the steel. IQ-Steels contain smaller and more fragmented inclusions and can handle much higher mechanical forces in all directions than conventional steels.

In simple load cases the bending fatigue strength can typically be increased by 40 to 100 percent, depending on steel used today. In multi-axial load cases increases of up to 130 percent can be achieved. As you strive to improve efficiency and reduce weight in your designs, you may want to downsize components or gain valuable space for other systems.

Uniform performance in all directionsSteel is normally anisotropic material by nature. Metal working will deform the inclusions formed in the metal. The result will be elongated defects in the rolling direction. A higher number of large defects can initiate cracks due to fatigue. IQ-Steel is designed to have small and isolated inclusions. The small and even sizes create the isotropic properties that can withstand heavy loads in all directions and thus makes it tailor-made for complex load cases. On top of this, one can combine the alloying content to get very little oxidation depth compared to conventional steels, resulting in corresponding improvements to surface properties. This could potentially eliminate surface enhancement processes such as shot peening. Benchmarking with VAR (vacuum arc remelting) steel shows that the fatigue properties obtained with IQ-Steel are equal to the fatigue properties of much more costly remelted material.

Ovako customer service

The BQ and IQ processes can be applied to all our steel grades. We can work closely with customers to optimise the steel supply chain to meet your requirements, including multiple product packages. The material is available in tubes, bars and rings. All of our services are underpinned by a detailed understanding of the industrial applications of our products, while paying as much attention as possible to your needs with regular direct contact. Ovako can advise you on how to best implement BQ-Steel and IQ-Steel for components in demanding applications.